How do I rewire my speakers to my headunit? I want to remove the amp and just run it off the headunit.?

Well, first it sounds as though whoever put the amp in in the first place did it wrong. If it shut off at high volume, it was probably all wired for a low impedance that what the amp could handle. As for the rewiring. Find the + and - leads for each spk (assuming theres only 4) and connect them to the the corresponding + and - leads out of the head, relating to their position in the vehicle. Most people leave the factory speaker wiring in the vehicle, or only cut off a small amount, so replacing the wires should be as simple as obtaining a color code or diagram for your vehicle and attaching the proper wires where they are needed.